The hepatitis C virus (HCV) is the agent responsible for the majority of hepatitis infections of the non-A non-B type. The seroprevalence of HCV infections varies between 0.3 abd 1.5% in the world population, possibly reaching 18% in some developing countries. Hundreds of millions of people are thus thought to be infected worldwide. Nine types and thirty subtypes of HCV have been described. The subtypes may be associated with a defined geographical distribution, type 1b being the most widespread worldwide. The progression to the chronic form occurs in 50% of cases, about 5 years after the primary infection. Persistent Chronic Hepatitis which is asymptomatic, but which exhibits a high circulating virus titer, is first observed, then Active Chronic Hepatitis becomes established. Twenty percent of chronic hepatitis progress to sclerosis of the liver within about ten years. Hepatocarcinoma may develop in the cirrhotic liver.
The present invention relates to a nucleic acid molecule that encodes a fusion polypeptide that comprises a first region consisting essentially of the C polypeptide of the hepatitis C virus (HCV) or a portion thereof that comprises a polypeptide region responsible for gene regulatory activity; and a second region consisting essentially of the envelope polypeptide (E1) of the virus or a portion thereof that comprises a site for cytoplasmic anchorage of the E1 polypeptide. The first region is fused by a peptide bond to the second region, and the fusion polypeptide is not cleaved by a mammalian protease.
In one embodiment, the present invention also pertains to a nucleic acid molecule that encodes a fusion polypeptide that has a C polypeptide of HCV or a portion thereof that comprises a first C polypeptide region responsible for gene regulatory activity and a second C polypeptide region responsible for the interaction with the E1 envelope polypeptide, wherein the site of interaction with the E1 polypeptide is between about 151 and about 173, or between about 173 and about 191. The fusion polypeptide also contains a E1 envelope polypeptide of HCV or a portion thereof that comprises a first E1 polypeptide region responsible for E1 cytoplasmic anchorage, and a second E1 polypeptide region responsible for the interaction of said second C polypeptide region, wherein the site for interaction with the C polypeptide is between about amino acid 330 and about amino acid 380. The C polypeptide is fused by a peptide bond to said E1 envelope polypeptide, and the C polypeptide comprises Cysteine172-Serine173-Phenylalanine174-Serine175 with at least one mutation between amino acid Nos 172 and 175. In a particular embodiment, the Serine residue in position 173 can be substituted by a Methionine residue or the Phenylalanine residue can be substituted by a Leucine residue.
The present invention also embodies a mixture that comprises a first polypeptide comprising at least a portion of the C polypeptide of HCV having a site for interaction with the E1 polypeptide of HCV; and a second polypeptide comprising at least a portion of the E1 polypeptide of HCV having a site for interaction with the C polypeptide of HCV and a site for cytoplasmic anchorage of the E1 polypeptide. In another embodiment the present invention includes a mixture that comprises a first polypeptide consisting essentially of the C polypeptide of the hepatitis C virus (HCV) or a portion thereof that comprises a polypeptide region responsible for gene regulatory activity; and a second polypeptide consisting essentially of the envelope polypeptide (E1) of the virus or a portion thereof that comprises a site for cytoplasmic anchorage of the E1 polypeptide. The mixture is not cleaved by a mammalian protease. The first and second polypeptides can be in a quantity that is substantially equimolar.
The present invention includes vaccine and/or pharmaceutical compositions comprising the nucleic acid sequences, polypeptide sequences or mixtures described herein. The present invention also relates to plasmids, vectors and cells that comprise the nucleic acid sequence of the present invention, or that encode the polypeptide sequence of the present invention.
The present invention also embodies methods of treating an individual having HCV, methods for preventing and individual from contracting or becoming affected with HCV, methods of vaccinating an individual against HCV, and methods for eliciting an immune response in an individual, comprising administering to the individual the nucleic acid molecules or polypeptide molecules described herein.